Recording DOS games?

2008-09-02 09:35:53 pm

Hello, I was looking into the rules and conditions of recording a speedrun, and I have a couple of questions. I know that no emulations is allowed, so does that mean that if I want to speedrun an old DOS game (for example, Day of the Tentacle), how would that be setup? I guess that would leave SCUMMVM out of the question, along with VMWare. My guess would be to boot the system into ms-dos, and run the game, and save the video through a vcr or another system. But the question is can I use utilities like MoSlo to bring my clock speed down if necessary, or is that also illegal, leaving me to gather up the hardware from the period the game was made? What about if I'm unable to get a sound card without DOS drivers? Would the video be acceptable with no sound? Would you need a video of the system booting up to ensure that no 'illegal' software is running?

Thread title:

Sir VG

2008-09-02 10:20:43 pm

Fucking Weeaboo

Getting a soundcard with DOS capabilities isn't too hard. Omni had some soundcards (mainly ISA) that worked fantastic with DOS.

Your bigger worry is actually CPU speed over sound issues. Usually a lot of DOS based games used CPU timings to play the game, and in newer computer a lot of them run WAY too fast. The best way to get around that is to get an older computer, like a Pent 133MHz, for instance. These can be found generally pretty cheap on eBay and might have your sound card that's DOS ready.

Enhasa

2008-09-03 07:42:58 am

everybody wanna tell you the meaning of music

The pain of recording DOS games is why we don't have any up yet. Sad

Saving video to DVD or VHS is the way to go like you said. Slowing your clock speed isn't allowed, sorry. I know you would use it for a good reason but it's abusable in general. Recording the sound is required too, sorry again. About recording system bootup, you can, and we would probably appreciate it if it's all the same to you, but it's not technically required.

Carcinogen

2008-09-03 07:58:27 am

Quote from Lord_VG:

These can be found generally pretty cheap on eBay and might have your sound card that's DOS ready.

Goodwill works too, as do the <$100 classifieds in the paper.

65

2008-09-03 10:42:38 am

I'll just use this thread and ask: How am I supposed to record 386-era games, which run way too fast even on my 166MHz Pentium? If I supposedly happen to obtain a comp like that that works, is it possible to record the feed you normally get to your monitor, or somehow get a TV out for that (if such things even exist).

What sort of solution should I be looking for? Or is it just impossible?

bmn

2008-09-03 12:52:48 pm

Regarding VMware, has there been a proper SDA discussion on it and similar apps like VirtualBox? As far as I understand, they emulate the system architecture and not, for example, the OS itself (as DOSBox does). I'd think they'd provide an authentic reproduction of whatever software is run on it.

Carcinogen

2008-09-03 01:48:56 pm

Quote from 65:

I'll just use this thread and ask: How am I supposed to record 386-era games, which run way too fast even on my 166MHz Pentium? If I supposedly happen to obtain a comp like that that works, is it possible to record the feed you normally get to your monitor, or somehow get a TV out for that (if such things even exist).

What sort of solution should I be looking for? Or is it just impossible?

When the TV-output on my Video Card didn't work, I had a VGA to Composite adapter. Shop around. They're available.

65

2008-09-03 02:04:22 pm

I'll keep that in mind, thanks. If I get such a thing from the NTSC regions, would that cause problems when I can't record NTSC with my DVD-player? (Ie., does it actually convert the signal, too?)

Lone_Kilted_Ninja

Edit history:

Lone_Kilted_Ninja: 2008-09-04 08:33:57 pm

2008-09-04 08:26:51 pm

Anything you can do I can do halfass

Quote from bmn:

Regarding VMware, has there been a proper SDA discussion on it and similar apps like VirtualBox? As far as I understand, they emulate the system architecture and not, for example, the OS itself (as DOSBox does). I'd think they'd provide an authentic reproduction of whatever software is run on it.

I'm a noob here, so this may be wrong, but emulation is emulation. It's actually sketchier to emulate the underlying hardware than the OS because that's where all the speed tweaks can happen- just think: console emulators don't emulate an OS either, just the hardware, and they're explicitly banned. If downclocking mods are also not kosher, it sounds like new PCs just won't cut it for old games.

Now that there are a whole host of digital TVs out there with VGA-in, you might be able to rig your old-but-VGA-capable graphics card directly to a new TV and see if the TV then has an output you can run to something else. Otherwise... ask teh internet. Back when I built most of a NES as a CE project, the graphics chip team found a way to patch the NES' composite out wires into a VGA monitor, so presumably all the requisite signals exist to go the other way, provided you have some cables that can be cannibalized and a bit of soldering skill.

Quote from 65:

I'll keep that in mind, thanks. If I get such a thing from the NTSC regions, would that cause problems when I can't record NTSC with my DVD-player? (Ie., does it actually convert the signal, too?)

Hrm. The big trick is always going to be getting the frequency of the signal right. In retrospect, the frequency out of the NES was fixed, and VGA supports a good range of parameters, so they may have just tweaked their reproduction of the video chip to output a "close" frequency that VGA was compatible with. You may need to dig up some driver hack to manually specify not only the resolution but also the frequency, overscan, etc. of your old graphics card, and yes, from a technical standpoint, I'd guess that any adapter hacked together for NTSC screens would not implicitly output PAL, and whether or not you could use it for PAL at all would likely hinge on whether it's a box with wires attached (i.e. something is going on inside to convert the signal) or just a bundle of wires (i.e. it just redirects signals and assumes the graphics card is outputting NTSC-TV-like values).

[quote="bmn"]
Regarding VMware, has there been a proper SDA discussion on it and similar apps like VirtualBox? As far as I understand, they emulate the system architecture and not, for example, the OS itself (as DOSBox does). I'd think they'd provide an authentic reproduction of whatever software is run on it.
[/quote]

I'm a noob here, so this may be wrong, but emulation is emulation.  It's actually sketchier to emulate the underlying hardware than the OS because that's where all the speed tweaks can happen- just think: console emulators don't emulate an OS either, just the hardware, and they're explicitly banned.  If downclocking mods are also not kosher, it sounds like new PCs just won't cut it for old games.

Now that there are a whole host of digital TVs out there with VGA-in, you might be able to rig your old-but-VGA-capable graphics card directly to a new TV and see if the TV then has an output you can run to something else.  Otherwise... ask teh internet.  Back when I built most of a NES as a CE project, the graphics chip team found a way to patch the NES' composite out wires into a VGA monitor, so presumably all the requisite signals exist to go the other way, provided you have some cables that can be cannibalized and a bit of soldering skill.

[quote="65"]
I'll keep that in mind, thanks. If I get such a thing from the NTSC regions, would that cause problems when I can't record NTSC with my DVD-player? (Ie., does it actually convert the signal, too?)
[/quote]
Hrm.  The big trick is always going to be getting the frequency of the signal right.  In retrospect, the frequency out of the NES was fixed, and VGA supports a good range of parameters, so they may have just tweaked their reproduction of the video chip to output a "close" frequency that VGA was compatible with.  You may need to dig up some driver hack to manually specify not only the resolution but also the frequency, overscan, etc. of your old graphics card, and yes, from a technical standpoint, I'd guess that any adapter hacked together for NTSC screens would not implicitly output PAL, and whether or not you could use it for PAL at all would likely hinge on whether it's a box with wires attached (i.e. something is going on inside to convert the signal) or just a bundle of wires (i.e. it just redirects signals and assumes the graphics card is outputting NTSC-TV-like values).

65

2008-09-06 06:48:01 am

I looked into it, and I think I've found a valid alternative. Should work perfectly for capturing Windows 3.1-based (and DOS-based, of course) programs that run on a 386-processor, don't you think? Supports both PAL and NTSC, too. There shouldn't be any(?) quality loss, because it's powered via USB (going to need another comp for that...)

Any experiences on the said product? Or similar?

Now I just need to find an ancient computer... and I think I know where to get it. I'm quite excited about this.

Lone_Kilted_Ninja

2008-09-06 05:28:43 pm

Anything you can do I can do halfass

Nice!
It occurred to me a little after the last post that I've seen switchboxes that can run, say, VGA, DVI, composite and S-vid to the same projector, but I wasn't sure offhand whether the output was TV cabling or PC cabling.
Something like that ought to do the job, just remember native resolution on classic TV is 640x480. Shouldn't be a problem for old DOS games, but anyone using this solution for Windows games may need to poke the monitor settings for the best image.

And just to be a know-it-all smart-ass, I'm thinking USB won't have anything to do with video quality apart from just saying "hey, this thing is at least as new as USB, so it's not completely archaic." I'd be much more concerned with the conversion of the resolution and the effects of overscan, but I doubt even those will be too bad. And if you need power for the USB, you could probably just bring over a powered USB hub if a full PC s too awkward.

65

2008-09-06 06:34:34 pm

It'd (=USB) better have something to do with image quality, because otherwise it wouldn't work as a powered splitter/adapter, but as a non-powered splitter, which would be bad.

I think TV's support resolutions somewhere up to 1024x720, because that's the resolution I recorded my MMX8 (PC) run at, and if it was better than that the full screen wouldn't show. That or it's recorder dependent.

nate

2008-09-06 07:08:45 pm

analog tv doesn't have resolution at all (thus "analog"). it scans from left to right for a certain number of lines and based on changes in the signal amplitude etc you get effects like luma and chroma. more info on wikipedia. basically there's nothing like it in the world of computers and games.

it's thought that a horizontal resolution of 720 pixels is more than sufficient to capture differences on each line and a vertical resolution of 480 pixels (ntsc) or 576 pixels (pal) is sufficient to capture all of the visible lines in those tv standards.

Lone_Kilted_Ninja

2008-09-08 10:21:47 am

Anything you can do I can do halfass

Fair 'nuff.
Horizontal res is analog, my limited experience with production gear suggests that most digital video for analog TV broadcast uses 720 pixel values per scanline, with "pixels" being a little narrower than they are tall. Some early digitizers I've used only capture 640 square pixels per line. My sense was that only a certain number of scanlines were encoded into every frame, however, hence TV standards being named by vertical "resolution" and whether or not scanlines interleave. 480 scanlines has been the standard I've seen on any 'low-def' setup I've used, production or recording, and in fact Wikipedia confirms that there are only 480 lines for visible data in NTSC, the remainder of the total 525 being frame synchronization. I've certainly pumped higher resolutions out of the S-video port on machines in the past, but even on large TVs, I tend to see the image just getting more aliased, not actually increasing in 'perceived' resolution.

And powered over unpowered will certainly up what the device can do, which was probably your point all along, I just wasn't seeing what USB-powered would get you over, say, wall-AC powered. The USB interface itself, apart from providing power, shouldn't be dictating how the video is treated, unless I'm gravely mistaken.

Fair 'nuff.
Horizontal res is analog, my limited experience with production gear suggests that most digital video for analog TV broadcast uses 720 pixel values per scanline, with "pixels" being a little narrower than they are tall.  Some early digitizers I've used only capture 640 square pixels per line.  My sense was that only a certain number of scanlines were encoded into every frame, however, hence TV standards being named by vertical "resolution" and whether or not scanlines interleave.  480 scanlines has been the standard I've seen on any 'low-def' setup I've used, production or recording, and in fact Wikipedia confirms that there are only 480 lines for visible data in NTSC, the remainder of the total 525 being frame synchronization.  I've certainly pumped higher resolutions out of the S-video port on machines in the past, but even on large TVs, I tend to see the image just getting more aliased, not actually increasing in 'perceived' resolution.

And powered over unpowered will certainly up what the device can do, which was probably your point all along, I just wasn't seeing what USB-powered would get you over, say, wall-AC powered.  The USB interface itself, apart from providing power, shouldn't be dictating how the video is treated, unless I'm gravely mistaken.

65

2008-11-03 11:14:49 am

Now I have an old computer and a way to record the VGA output + sounds, so I'm all set to go. But I want to go deeper; to run games that have PC speaker sounds only. 'Nfortunately, I have no idea how to record those sounds; it's practically impossible unless I'm supposed to stick a microphone into my computer while I'm running the game (which sounds a very safe thing to do...)

I'm hoping to get a ruling on what to do with these type of games. Can I run them without sound or does SDA have some sort of recommendation for this sort of thing?

nate

2008-11-03 12:10:55 pm

can you just splice a miniplug jack onto the system's speaker line? don't know much about old school pc sound unfortunately.

65

2008-11-03 01:02:00 pm

I don't know how I should do that. I know I have a broken PC speaker (the soldering broke) at my parents' house somewhere that I could use for the job, but I'm not very good at soldering or other handiwork of that sort. I suppose it's not technically impossible, but I would need some detailed descriptions to avoid life threatening situtations while I'm testing it.

I try to avoid excessive messing with the hardware as a PC as old as this is not too easy to come by, considering it still works perfectly well.

Enhasa

2008-11-03 02:53:55 pm

everybody wanna tell you the meaning of music

I'm not Nate and you should definitely listen to him and not me, but PC speaker sounds like total ass anyway. I personally wouldn't mind if you used a mic to record it. Lo-fi ftw.

Lag.Com

2008-11-03 03:37:53 pm

sda loyalist

Commander Keen's sound effects are total classic though. It would be a shame not to reproduce them in super-hi-fi for all to hear.

Enhasa

2008-11-03 05:59:02 pm

everybody wanna tell you the meaning of music

lol, and you say I don't understand you Wink

Poesta

2008-11-05 03:39:37 am

Yarr

Is it allowed to use a MS-DOS clone like PC-DOS, DR-DOS or FreeDOS for running DOS games? They aren't emulators, and FreeDOS also supports modern hardware. Also, is it allowed to run DOS inside a virtual machine like VMWare or VirtualBox? If it is possible to somehow get DirectX/OpenGL output from a virtual machine, you could record it using Fraps. Using FreeDOS you can record demos on Doom-like games, or use a capture device.

Also, here is a guide on recording from the PC speaker (first Google result >_>). It basically says that the best way is to use a mic. The other option is to connect the speaker to a a stereo but then you'll have to screw around with the electrical circuit.

DRybes

Edit history:

DRybes: 2008-11-05 07:02:12 am

2008-11-05 06:51:59 am

O Zlda?

Finally my audio knowledge can find a use Smiley

You can directly run the 2 PC speaker wires into the line-level input (use a mono miniplug) of another PC and record the sound that way and sync it up with the video afterwards. I wouldn't recommend the mic input, has to be the (usually blue) line-level, cause the pulses are several volts. You will have to use an audio editing program and apply a low or bandpass filter to the sound to get rid of harmonics because of how the PC speaker works... however, after that, it will sound better than if you used a mic (which is going to be the same amount of work anyway, involving a seperate PC, and probably some processing to remove outside noise and static).

If you have any audio device specifically made with a speaker-level input, then you can use that to get the signal into a PC for recording, and then you shouldn't have to do any processing. An example would be the convertor devices specifically made for cars where your factory radio doesn't have RCA/line level outputs, and you want to run a car amp that has RCA ins. It's a pretty simple circuit, passive, that converts the speaker output to RCA, which can patch directly into a line input miniplug. If you have one of those laying around it may be of use (they are available in increasing amounts of stores that sell car audio equipment, usually cost $10-$20). I don't think it's necessary if you have a half decent audio editor though... but then again, I never tried running a PC speaker into a line in. According to wikipedia they use a lot of audio tricks to make some of the more complex PC speaker sounds, some of which take advantage of the fact that it's a cone speaker, but an audio editor should be able to process that into something usable.

Edit: yep, apparently the line input works fine, but you can put a cap across the wires to block DC, eliminating a lot of the processing (I guess I should have read that guide before posting, all I had to share was in there). And there's other things to do if that's still too much voltage for your sound card... so that car adapter I mentioned is the down-and-dirty solution, since its more or less the circuit they're describing (I think it has a few other things in it too, since it handles variable wattage input, and there's a pot to adjust the output voltage).

Finally my audio knowledge can find a use :)

You can directly run the 2 PC speaker wires into the line-level input (use a mono miniplug) of another PC and record the sound that way and sync it up with the video afterwards. I wouldn't recommend the mic input, has to be the (usually blue) line-level, cause the pulses are several volts. You will have to use an audio editing program and apply a low or bandpass filter to the sound to get rid of harmonics because of how the PC speaker works... however, after that, it will sound better than if you used a mic (which is going to be the same amount of work anyway, involving a seperate PC, and probably some processing to remove outside noise and static).

If you have any audio device specifically made with a speaker-level input, then you can use that to get the signal into a PC for recording, and then you shouldn't have to do any processing. An example would be the convertor devices specifically made for cars where your factory radio doesn't have RCA/line level outputs, and you want to run a car amp that has RCA ins. It's a pretty simple circuit, passive, that converts the speaker output to RCA, which can patch directly into a line input miniplug. If you have one of those laying around it may be of use (they are available in increasing amounts of stores that sell car audio equipment, usually cost $10-$20). I don't think it's necessary if you have a half decent audio editor though... but then again, I never tried running a PC speaker into a line in. According to wikipedia they use a lot of audio tricks to make some of the more complex PC speaker sounds, some of which take advantage of the fact that it's a cone speaker, but an audio editor should be able to process that into something usable.

Edit: yep, apparently the line input works fine, but you can put a cap across the wires to block DC, eliminating a lot of the processing (I guess I should have read that guide before posting, all I had to share was in there). And there's other things to do if that's still too much voltage for your sound card... so that car adapter I mentioned is the down-and-dirty solution, since its more or less the circuit they're describing (I think it has a few other things in it too, since it handles variable wattage input, and there's a pot to adjust the output voltage).

Poesta

2008-11-06 08:11:32 am

Yarr

Bump.

Quote:

Is it allowed to use a MS-DOS clone like PC-DOS, DR-DOS or FreeDOS for running DOS games? They aren't emulators, and FreeDOS also supports modern hardware. Also, is it allowed to run DOS inside a virtual machine like VMWare or VirtualBox? If it is possible to somehow get DirectX/OpenGL output from a virtual machine, you could record it using Fraps. Using FreeDOS you can record demos on Doom-like games, or use a capture device.

DRybes

2008-11-06 12:22:14 pm

O Zlda?

Virtual machines, emulators, and application layer interfaces are never going to be allowed.

Is what you're asking about a legitimate Disk Operating System that runs on 386, just not MS-DOS?

Enhasa

2008-11-07 08:08:54 am

everybody wanna tell you the meaning of music

Sorry I didn't see this earlier.

Somebody else on staff can object if they want, but I always assumed FreeDOS, PC-DOS, DR-DOS, etc are ok (since they are actual operating systems) and VMWare and VirtualBox are not.